Thriller starring Idris Elba, Ali Larter and Beyonce Knowles. Derek Charles (Elba), a successful asset manager who has just received a huge promotion, is blissfully happy in his career and his marriage to the beautiful Sharon (Beyuonce Knowles). But when new office temp Lisa (Ali Larter) becomes obsessed with Derek and starts stalking him, all the things he's worked so hard for are placed in jeopardy.